chromium/chrome/test/data/extensions/csp/add_iframe_extension/manifest.json

{
    "name": "Add iframe",
    "version": "1",
    "manifest_version": 2,
    "content_scripts": [{
        "js": ["content_script.js"],
        "matches": ["*://*/*"]
    }],
    "permissions": [
        "*://*/*"
    ]
}